Welding current controlling method in arc welding process using consumable electrode upon detection of constriction

a technology of welding current and control method, which is applied in the direction of welding apparatus, arc welding apparatus, manufacturing tools, etc., can solve the problems of easy generation of spatter, large amount of spatter, and intense vibration in the molten pool to generate spatter, so as to reduce the generation of spatter, prevent accidental short-circuiting, and restrict the vibration in the molten pool

Active Publication Date: 2011-04-05
DAIHEN CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The method achieves a gradual change in arc force, reducing spatter generation and preventing accidental short-circuiting, while optimizing wire melting speed and maintaining stable welding conditions.

Problems solved by technology

This causes large growth of the pressure (i.e. arc force) produced by the arc 3 to the molten pool 2a, resulting in generation of a large amount of spatter.
Firstly, it includes sharp surge of the welding current Iw at the time instant t4, which is the end of the delay period Td following an arc regeneration. This current surge causes rapid change of arc force, resulting in intense vibration in the molten pool to generate spatter.
Secondly, the vibration in the molten pool may cause the tip of the wire to make contact with the molten pool, resulting in accidental occurrence of short-circuiting again. Different from normal and stable short-circuiting, this kind of accidental short-circuiting is unstable and cause to generate spatter easily.
In order to restrict generation of spatter, the above-mentioned current controlling method upon detecting of a constriction employs special circuit configuration which costs high.

Method used

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  • Welding current controlling method in arc welding process using consumable electrode upon detection of constriction
  • Welding current controlling method in arc welding process using consumable electrode upon detection of constriction
  • Welding current controlling method in arc welding process using consumable electrode upon detection of constriction

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first embodiment

[0068]FIG. 1 is a block diagram of a power source for a welding current controlling method in an arc welding process using a consumable electrode upon detection of a constriction according to the present invention. In the figure, blocks identical to those in the above-described conventional method shown in FIG. 6 are given the same reference numbers and no description is made. The blocks different from FIG. 6 are drawn with dashed lines in FIG. 1, and will be described below.

[0069]The inclination setting circuit SR outputs the inclination setting signal Sr. The current inclination controller NSC, which provides time change of current with an inclination upon detection of a constriction, receives the delay period setting signal Tdr, the uprise period setting signal Tur, the first current level setting signal Imr, the second current level setting signal Ihr, the neck detection signal Nd, and the inclination setting signal Sr, and outputs the switching signal Sw for power characteristi...

second embodiment

[0074]According to the present invention, the inclination of time change of the welding current has different values at the first stage and the second stage of the uprise period which starts after the delay period beginning with an arc regeneration. In this embodiment, the inclination may change continuously along a curve or change in a step-like manner.

[0075]FIG. 3 is a block diagram of a power source for a welding current controlling method in an arc welding process using a consumable electrode upon detection of a constriction according to the second embodiment of the present invention. In the figure, blocks identical to those in the above-described first embodiment in FIG. 1 are given the same reference numbers and no duplicated description. The blocks different from FIG. 1 are drawn with dashed lines in FIG. 3, and will be described below.

[0076]The inclination trajectory memorizing circuit SM outputs the trajectory memorizing signal Sm.

[0077]The wire feeding speed setting circui...

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Abstract

A welding current controlling method is provided for an arc welding process using a consumable electrode and including an alternate repetition of a short-circuiting state and an arc generating state occurring between the consumable electrode and a base material. In the method, a neck detection is performed for the molten electrode in the short-circuiting period of time to determine if a new arc is established between the consumable electrode and the base material. Upon detection of the neck, the welding current is sharply decreased. After the new arc is established, the welding current is increased from a low level to a high level with a predetermined inclination selected for reducing vibration to the molten pool.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to an arc welding process using a consumable electrode. In particular, the present invention relates to a welding current controlling method for reducing the spattering of molten metal by sharply decreasing the welding current immediately before a new arc is established.[0003]2. Description of the Related Art[0004]FIG. 5 illustrates a conventional arc welding process using a consumable electrode or welding wire. The figure includes a diagram showing waveforms of welding current Iw and welding voltage Vw, while also including a diagram showing the metal transfer of the welding wire in a plastic state. As seen from the figure, the welding process comprises an alternate repetition of a short-circuiting time or period Ts and an arc generating time or period Ta.[0005]More specifically, Waveform (A) in FIG. 5 shows the change of the welding current Iw with time (the current Iw passes through the ...

Claims

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Application Information

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Patent Type & AuthorityPatents(United States)
IPC IPC(8): B23K9/10B23K9/06
CPCB23K9/092
InventorERA, TETSUOIDE, AKIHIRO
OwnerDAIHEN CORP